Lina Forero, Robert Castilla.
The aim of this study is to evaluate and compare the response of the maxilla bone, with an anisotropic nature, in the peri-implant region when osseointegrated implants are placed in different angles, based on the stress and strain distribution by the finite element method. We focus on implant models from brands available in the metropolitan area of Bucaramanga, Colombia. Twenty-seven models were fabricated to reproduce a portion of a maxilla bone (upper first molar region) with two types of implants which have different thread geometry (squared and v shaped) and material (Ti-6AL-4V ELI and grade IV Titanium). Compressive axial (150N) and oblique load (150 N at 45° angle) were applied to isotropic and anisotropic models of the bone tissues. Complete osseointegration was assumed. For data analysis, the maximum stress and strain (according to the von Misses criterion) were used. Results demonstrated that, the increasing of the implant inclination leads to a more critical behavior, especially for strain distribution which could not surpass the limit of 4000 microstrain. Oblique loading was more detrimental to stress and strain distribution than axial load, also, these were more efficiently distributed by squared thread implants. The proposed isotropic models in this study failed to represent the performance of real bone conditions which are more similar to an anisotropic model. Squared thread implants are a better option for osseointegrated dental implant treatments, even when inclined positions are required. More detailed models should be created to represent the use of bone allografts in a patient after bone resorption happened.